MI 3290 Earth Analyser
Technical specifications
143
15.11.1 Digital filtering technique
The Earth Analyser uses a high - resolution 52k SPS (samples per second) analog to digital converter to
obtain all the different analog signals like input voltage (Uh), current (ie)… to digital results.
Example
Test objects description and schematics wiring diagram:
Selective (Flex Clamp)
Re
10
Rc and Rp
2 k
Test frequency
128 Hz
If1
19,7 mA
Inoise
5 Arms @ 50 Hz
SNR
-48 dB
H
S
G
F1
Re
Rp
Rc
ES
E
Inoise
If1
Ie
Using the Selective FFT filter algorithm.
Frequency [Hz]
A
m
pl
itu
de
[d
B
]
1k
10
100
Inoise @ 50
Hz
If1 @ 125 Hz
The Earth Analyser will measure only analog signal (If1) that is generated by the instrument and will filter
out any other frequencies (Inoise). So frequencies different from the measurement frequency will not
influence on the measurement result.
15.12 Sub-results in measurement functions
Sub-result
Measuring range
Resolution
Uncertainty
Rp, Rc
0
… 49,9 k
1
… 0,1 k
(8 % of r 3 digits)
Re
0,010
… 19,9 k
0,001
… 0,1 k
(8 % of r 3 digits)
Ie
0,01 mA … 999 mA
0,01 mA … 1 mA
(3 % of r 3 digits)
Ic
0,01 mA … 9,99 A
0,01 mA … 0,01 A
(5 % of r 3 digits)
If1, If2, If3, If4
0,1 mA … 49,9 A
0,1 mA … 0,1 A
(5 % of r 3 digits)
Zsel1, Zsel2,
Zsel3, Zsel4
0,001
… 19,9 k
0,001
… 0,1 k
(8 % of r 3 digits)
f
40,0 Hz … 25,0 kHz
0,1 Hz … 0,1 kHz
(0,2 % of r 1 digit)
Igen
0,01 mA … 999 mA
0,01 mA … 1 mA
(2 % of r 2 digits)
If_sum
0,01 mA … 99,9 A
0,01 mA … 0,1 mA
(5 % of r 3 digits)
Iac
0,1 mA … 999 mA
0,1 mA … 1 mA
(2 % of r 2 digits)
R, X
1
… 19,9 k
1
… 0,1
Indication only
φ
1 ° … 360 °
1 °
Indication only
Idc
0,1 mA … 999 mA
0,1 mA … 1 mA
(2 % of r 2 digits)
